Originally Posted by
Bob Dopolina
This is exactly what both Shimano and Campagnolo have recognized. Side loading a cartridge bearing increases friction. There is no mystery here.
I wander if they have yet realized that in a bicycle hub, there is almost never any side (axial) loading. Since a bicycle only has two wheels, if there was axial loading, it would fall over. The only exception to this is if the bike is rocked vigorously, like in a sprint.